The markings on soccer fields, consisting of straight lines and curves, must be renewed periodically. This is done by driving stakes into the ground at certain measuring points and stretching a cord between two stakes, along which cord a straight-line marking is applied to the grass, or by fastening a cord to a stake and inscribing a circle around the stake with the end of the cord. The stakes are then removed. Since the markings can shift on the grass over time, or since they are occasionally washed away, the measuring points for insertion of the stakes must be remeasured periodically, which is expensive.